Water polo is a team water game. A team consists of six field players and one goalkeeper. The winner of the game is the team that scores more goals.

Water polo was developed in Europe and the United States as two separate sports. In the United States it was termed softball water polo, with the ball being an unfilled bladder.

The sport was very rough, often degenerating into numerous fights. In 1897, Harold Reeder of New York formulated the first American rules for the discipline, which were aimed at decreasing the excessive roughness of the game.

The game is called water polo because players initially rode on floating barrels that resembled mock horses, and swung at the ball with mallet-like sticks, similar to those used in equestrian polo.

Ultimately, the European style of water polo predominated and today it is the form of the game practised universally.

It is more scientific, faster and less dangerous than the original American game. The current game consists of seven-man teams playing four seven-minute periods.